Quick question - would you be happy with this wheel?

Quick question - would you be happy with this wheel?

Author
Discussion

Kell

Original Poster:

1,708 posts

207 months

Thursday 25th August 2016
quotequote all
Had a wheel rebuilt for my Brompton and when it came back it doesn't look right to me.

Spokes seem to cross over the wrong way as they're really bowed.

Some even bend two ways.

Is it just me? Or is this a bad build?










Edited by Kell on Thursday 25th August 09:41

Pachydermus

973 posts

111 months

Thursday 25th August 2016
quotequote all
yes, it's crap. the inside spokes should be under and the outside spokes over.
Look here to see it done right.

neenaw

1,212 posts

188 months

Thursday 25th August 2016
quotequote all
I've no idea about wheel building but that looks awful to me!

MDMA .

8,849 posts

100 months

Thursday 25th August 2016
quotequote all
looks terrible. possibly the worst 2 cross I've seen ( really should be 3 cross on the rear / DS ). I would take it back straight away and get someone else to build it for you.

Kell

Original Poster:

1,708 posts

207 months

Thursday 25th August 2016
quotequote all
Should look like this:


upsidedownmark

2,120 posts

134 months

Thursday 25th August 2016
quotequote all
Actually I think it looks terrible because it is such a small wheel with such short spokes / big hub. Best as I can tell from the photos, the spokes are laced correctly for a 2x DS. The 'leading' spokes should always pass behind / under the trailing spokes on the last (outermost) crossover. That way when they're in tension (under drive) and the trailing ones are de-tensioned, they tend to pull straighter and 'tighten' the trailing ones..

Woody

2,187 posts

283 months

Thursday 25th August 2016
quotequote all
I'm no expert, but some of those spokes look quite bent.
I'd get someone else to rebuild it.

AyBee

10,522 posts

201 months

Thursday 25th August 2016
quotequote all
upsidedownmark said:
Actually I think it looks terrible because it is such a small wheel with such short spokes / big hub. Best as I can tell from the photos, the spokes are laced correctly for a 2x DS. The 'leading' spokes should always pass behind / under the trailing spokes on the last (outermost) crossover. That way when they're in tension (under drive) and the trailing ones are de-tensioned, they tend to pull straighter and 'tighten' the trailing ones..
But surely it makes sense that the outside spokes go outside the inside spokes? That's just common sense (but not what has happened on this wheel).

upsidedownmark

2,120 posts

134 months

Thursday 25th August 2016
quotequote all
Outside spoke should go outside, inside for a 2x, or outside, outside, inside for a 3x. Common sense isn't always what you might think.

[ETA the rules *might* change for very small wheels] Check any regular sized wheel and you should see it as above; it's so that the wheel tensions its self under drive.

Edited by upsidedownmark on Thursday 25th August 13:53

louiebaby

10,651 posts

190 months

Thursday 25th August 2016
quotequote all
I can chuck a couple of pics of my Brompton rear up tonight when I get home, but I think the idea is that the spokes come out of the rim at a 90 angle, right?

Looks suspect, not an expert.

Kell

Original Poster:

1,708 posts

207 months

Thursday 25th August 2016
quotequote all
Surprisingly the pics of new wheels show the nipples at quite extreme angles - I thought the same as you, that they look too extreme.

It's back with the shop now and they're going to call Brompton to see what the correct lacing pattern is.

I did know that often the spokes are crossed but that really didn't look right to my (admittedly not very technical) eyes.

upsidedownmark

2,120 posts

134 months

Thursday 25th August 2016
quotequote all
The only way the spokes can come out at a 90 degree angle is if it is radially laced, and that's something you can't do on a driving wheel (only on a rim braked front). The smaller the wheel, the more crosses you have, and the larger the hub, the more extreme the angle.

Not saying that wheel *is* perfect / spot on - I don't know. To me, every brompton wheel I've seen does look hellish precisely because they're damn small, and have a lot of crosses going on. I've built a few full sized wheels, so know enough to be dangerous, but not an expert either smile

Edited by upsidedownmark on Thursday 25th August 14:38

Pachydermus

973 posts

111 months

Thursday 25th August 2016
quotequote all
whatever the lacing pattern should be there is no way that the spokes should be physically bent to fit.

gazza285

9,780 posts

207 months

Thursday 25th August 2016
quotequote all
There's no reason to lace the inner spokes and outer spokes like that on a small wheel, it just makes to spokes look wrong, plus you have to bend the spokes to lace the wheel up. Two cross is correct, but not laced together, rebuild time...

Kell

Original Poster:

1,708 posts

207 months

Friday 26th August 2016
quotequote all
Well the shop's admitted they got it wrong.

While it's correct that a 2x lacing pattern on larger wheels is as mine was done, that's not how Brompton do it, nor what they recommend.

I'm a big believer in giving people a second chance and letting them correct their mistakes, so was happy to take it back there.

Should get a look at it tonight as my Dad's said he'll pick it up for me today.




AyBee

10,522 posts

201 months

Friday 26th August 2016
quotequote all
I'm not even convinced they got the 2-lacing pattern correct either, there's no way those spokes should be bent around each other, spokes exiting the outside of the hub should remain outside of all spokes, not cross under the spokes which exit the inside of the hub! Just give it a close look before you part with any money - it doesn't look like they really know what they're doing.

upsidedownmark

2,120 posts

134 months

Friday 26th August 2016
quotequote all
For a ?20? inch wheel on my dahon, they're laced (outside / inside), and every other bike I own from mountainbike to the TT. This is totally normal AND correct for a 'regular' wheel. If you want the wheel to hold tension, that's what you do (otherwise the trailing spokes unload and 'work' loose). It may run counter to your intuition AyBee, but take a look at any old 700c wheel, you'll see the same. Spokes 'bend' around each other with the 'leading' spokes going ouside-inside. Take a look at sheldon brown's pages if you want confirmation.

However my mate's brompton (which I think is an 18 inch?), they do indeed stay outside - it's 2x laced fully outside. If you went 3x, the spoke angles would be absurd, 1x wouldn't really be enough, and you just can't lace a driving wheel radially for obvious reasons.

Presumably with the wheel being so small you reach a point where it's just too much, and conversely there's probably less torque induced slackening of the trailing spokes with a small wheel

gazza285

9,780 posts

207 months

Friday 26th August 2016
quotequote all
Motorcycle wheels don't need the spokes laced over each other to keep tension and neither do bicycle wheels, but it is the accepted norm on large wheels. I wouldn't lace the spokes over on a wheel this size, due to the outcome seen in the OP's wheel.